My Colt Sporter has a barrel marked 5.56mm and a lower reciever marked .223. I honestly think that most manufacturers are either just getting lazy or they're trying to skirt US government export laws. I've also shot both 5.56 and .223 out of my rifle with zero problems.
Firing 5.56 out of an M&P15I
- Thread starter pierrody
- Start date
In the old days , no one really cares.
Problem starts when people start shooting crappy surplus ammo in some of the match chamber.
To be honest, PERSONALLY, I will not hesitate to shoot "quality"(ie, 5.56 made by NATO or reputable 1st world countries) 5.56 out of a .223 rifle, unless it is advertised to have a tight chamber. If you choose to shoot "wolf" steel case ammo or some 3rd s**thole ammo rotated out of their rotten warehouses, don't expect 100% function.
Problem starts when people start shooting crappy surplus ammo in some of the match chamber.
To be honest, PERSONALLY, I will not hesitate to shoot "quality"(ie, 5.56 made by NATO or reputable 1st world countries) 5.56 out of a .223 rifle, unless it is advertised to have a tight chamber. If you choose to shoot "wolf" steel case ammo or some 3rd s**thole ammo rotated out of their rotten warehouses, don't expect 100% function.
- Location
- 54°52'56"N 112°10'7"W Alpha Bravo
so if the differences are strictly pressure between the two, then there would defiantly be no damage or danger shooting .223 out of a 5.56 rifle, true???
The pressure differences result from different methods of measuring pressures, not because actual pressures are actually different. Dimensionnal differences are in the throat/leade portions of the chambers. NATO ammunition will fit a NATO chamber correctly. With .223, this is not guaranteed. Different specs, different bullet ogives, different bullets. IF a bullet is jammed into the leade, pressures can spike.
A rifle with a 5.56 NATO spec. chamber, with a .223 stamp applied to it for export purposes will be a problem for the mfr. if the export control folks get wind of it.
Haven't checked recently, but Federal made two different hardpoint loads, one 5.56 spec, the other .223. Different cartridges, different stock numbers.
SAAMI has their position, many shooters report no problems.
Basically, shooters have to make a decision.
A rifle with a 5.56 NATO spec. chamber, with a .223 stamp applied to it for export purposes will be a problem for the mfr. if the export control folks get wind of it.
Haven't checked recently, but Federal made two different hardpoint loads, one 5.56 spec, the other .223. Different cartridges, different stock numbers.
SAAMI has their position, many shooters report no problems.
Basically, shooters have to make a decision.
X2 ..happness is a warm gun...
" Death Cheated Yet Again "
Back from the range after a few hundred rounds, we are all alive, it was a mix/match of 223/556 762/308 from a myriad of rem 700p's, colt m4's and an oly arms ar15.........again nary a hiccup
I was not so lucky... I was firing some PMC K100 5.56 out of my .223 marked Stag today and unfortunately I was killed... In lieu of flowers donations can be made by EMT to 22ivan
Back to the original question. If you *really* want to know, order the ".223/5.56? Gage" (not my spelling) from http://www.m-guns.com/tools.php .
From the site:
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This gage tells you if you have a chamber that is 5.56 NATO (or larger), or something shorter/smaller.
The gage looks a lot like a headspace gage but it does not gage headspace. It comes with its own rod which you thread into the tapped hole in the back of the gage. Unload and open your rifle, pull the bolt group, make sure the chamber is clean so there is no false reading, and drop the gage in. If the gage's shoulder "clinks" off on the shoulder of the chamber and the gage drops or pulls free without sticking or resistance, you have a chamber that is 5.56 NATO or larger. If the gage goes in and wants to stick, as in, you let it in and it pulls with a little resistance, or you try and turn it but it does not turn freely, you are short of 5.56 NATO and probably have a .223 chamber. You can color it up with a Sharpie, put it in and spin it (clockwise) to observe where it's contacting the chamber first.
Note that the gage will also stick in a .223 Wylde chamber since the Wylde's freebore is smaller in diameter than the 5.56 NATO's. It's my opinion that the Wylde chamber ought to be OK with 5.56 NATO ammo, but I have not delved into this scientifically. I don't own anything with the Wylde chamber, so I have no first-hand experience with it. The smaller freebore, I suppose, would make it more crud-sensitive.
Probing either a .223 SAAMI or .223 Wylde chamber with this gage will not harm the chamber unless you decide to really try by hammering it in. Don't do that.
Price is $44, add $10 for Priority Mail, or $5 for first class.
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All above is US dollars before duty etc.
From the site:
---------------------------------------------
This gage tells you if you have a chamber that is 5.56 NATO (or larger), or something shorter/smaller.
The gage looks a lot like a headspace gage but it does not gage headspace. It comes with its own rod which you thread into the tapped hole in the back of the gage. Unload and open your rifle, pull the bolt group, make sure the chamber is clean so there is no false reading, and drop the gage in. If the gage's shoulder "clinks" off on the shoulder of the chamber and the gage drops or pulls free without sticking or resistance, you have a chamber that is 5.56 NATO or larger. If the gage goes in and wants to stick, as in, you let it in and it pulls with a little resistance, or you try and turn it but it does not turn freely, you are short of 5.56 NATO and probably have a .223 chamber. You can color it up with a Sharpie, put it in and spin it (clockwise) to observe where it's contacting the chamber first.
Note that the gage will also stick in a .223 Wylde chamber since the Wylde's freebore is smaller in diameter than the 5.56 NATO's. It's my opinion that the Wylde chamber ought to be OK with 5.56 NATO ammo, but I have not delved into this scientifically. I don't own anything with the Wylde chamber, so I have no first-hand experience with it. The smaller freebore, I suppose, would make it more crud-sensitive.
Probing either a .223 SAAMI or .223 Wylde chamber with this gage will not harm the chamber unless you decide to really try by hammering it in. Don't do that.
Price is $44, add $10 for Priority Mail, or $5 for first class.
-----------------------------------------------
All above is US dollars before duty etc.
